No abstract

The industrialization of quantum dot light-emitting diodes (QLEDs) requires the use of less hazardous cadmium-free quantum dots, among which ZnSe-based blue and InP-based green and red quantum dots have received considerable attention. In comparison, the development of InP-based green QLEDs is lagging behind. Here, we prepare green InP/ZnSe/ZnS quantum dots with a diameter of 8.6 nm. We then modify the InP quantum dot emitting layer by passivation with various alkyl diamines and zinc halides, which decreases electron mobility and enhances hole transport. This, together with optimizing the electron transport layer, leads to green 545 nm InP QLEDs with a maximum quantum efficiency (EQE) of 16.3% and a current efficiency 57.5 cd/A. EQE approaches the theoretical limit of InP quantum dots, with an emission quantum yield of 86%.

In this study, the chromophore 3,4,9,10-perylenetetracarboxylic diimide (PDI) is anchored with phenyl substituents at the imide N site, followed by thionation, yielding a series of thione products 1S-PDI-D, 2S-cis-PDI-D, 2S-trans-PDI-D, 3S-PDI-D, and 4S-PDI-D, respectively, with n = 1, 2, 3, and 4 thione. The photophysical properties are dependent on the number of anchored thiones, where the observed prominent lower-lying absorption is assigned to the S 0 → S 2 (ππ*) transition and is red-shifted upon increasing the number of thiones; the lowest-lying excited state is ascribed to a transition-forbidden S 1 (nπ*) configuration. All nS-PDIs are non-emissive in solution but reveal an excellent twophoton absorption cross-section of >800 GM. Supported by the femtosecond transient absorption study, the S 1 (nπ*) → T 1 (ππ*) intersystem crossing (ISC) rate is > 10 12 s −1 , resulting in ∼100% triplet population. The lowest-lying T 1 (ππ*) energy is calculated to be in the order of 1S-PDI-D > 2S-cis-PDI-D ∼ 2S-trans-PDI-D > 3S-PDI-D > 4S-PDI-D, where the T 1 energy of 1S-PDI-D (1.10 eV) is higher than that (0.97 eV) of the 1 O 2 1 Δ g state. 1S-PDI-D is further modified by either conjugation with peptide FC131 on the two terminal sides, forming 1S-FC131, or linkage with peptide FC131 and cyanine5 dye on each terminal, yielding Cy5-1S-FC131. In vitro experiments show power of 1S-FC131 and Cy5-1S-FC131 in recognizing A549 cells out of other three lung normal cells and effective photodynamic therapy. In vivo, both molecular composites demonstrate outstanding antitumor ability in A549 xenografted tumor mice, where Cy5-1S-FC131 shows superiority of simultaneous fluorescence tracking and targeted photodynamic therapy.

Organic molecules having emission in the NIR(II) region are emergent and receiving enormous attention. Unfortunately, attaining accountable organic emission intensity around the NIR(II) region is hampered by the dominant internal conversion operated by the energy gap law, where the emission energy gap and the associated internal reorganization energy λ int play key roles. Up to the current stage, the majority of the reported organic NIR(II) emitters belong to those polymethines terminated by two symmetric chromophores. Such a design has proved to have a small λ int that greatly suppresses the internal conversion. However, the imposition of symmetric chromophores is stringent, limiting further development of organic NIR(II) dyes in diversity and versatility. Here, we propose a new concept where as far as the emissive state of the any asymmetric polymethines contains more or less equally transition density between two terminated chromophores, λ int can be as small as that of the symmetric polymethines. To prove the concept, we synthesize a series of new polymethines terminated by xanthen-9-yl-benzoic acid and 2,4-diphenylthiopyrylium derivatives, yielding AJBF1112 and AEBF1119 that reveal emission peak wavelength at 1112 and 1119 nm, respectively. The quantum yield is higher than all synthesized symmetric polymethines of 2,4-diphenylthiopyrylium derivatives (SC1162, 1182(SC1162, , 1185(SC1162, , and 1230) in this study. λ int were calculated to be as small as 6.2 and 7.3 kcal/mol for AJBF1112 and AEBF1119, respectively, proving the concept. AEBF1119 was further prepared as a polymer dot to demonstrate its in vitro specific cellular imaging and in vivo tumor/bone targeting in the NIR(II) region.

Our experience has shown the wide arc of rotation, large skin replacement potential, multiple components and reliability of pedicled ALT flaps. They are technically simple to apply as myocutaneous/fasciocutaneous flaps with minimal donor site morbidity.

The pedicle ALT flap is a more effective treatment than the TFL flap for the surgical management of trochanteric sores. The hatchet-shaped TFL flap should be reserved for the reconstruction of recurrent trochanteric sores or for use in the critically ill patient who cannot tolerate longer anesthesia and operation time.

For selected patients who have advanced stage cancer, surgical sequelae after free flap surgery, unable to tolerate microsurgery, or special defect location, pedicled lower trapezius musculocutaneous flap provides efficient and effective reconstruction for complex defects especially in the head and neck.

Inverted perovskite solar cells (PSCs) mainly adopt polytriarylamine (PTAA) for the hole transport material (HTM), which usually brings about inferior interfacial contact owing to their hydrophobicity, high‐lying highest occupied molecular orbital energy level, and deficiency of passivation groups. Herein, a series of donor–π–acceptor (D–π–A) type small molecules is demonstrated based on 2,2′:6′,2″‐terpyridine (TPy) as the acceptor moiety, benzene ring as the π‐linker, and incorporating various donors to act as HTMs. These TPy‐based molecules coated atop PTAA manipulate the energy level and surface wettability, but the incorporation of the phenoxazine (POZ) donor can be prominent for enhancing charge transport and defect passivation, thereby simultaneously addressing the above‐mentioned issues. The highest power conversion efficiency of 22.36% can be achieved with an open‐circuit voltage (VOC) of 1.15 V, a short‐circuit current density (JSC) of 23.96 mA cm−2, and a fill factor (FF) of 81.16% for the optimized POZ‐TPy‐modified device. Moreover, the power PCE of a large POZ‐TPy‐modified device (1.96 cm2) can still reach more than 21%. These results are among one of the highest efficiencies for inverted PSCs, indicating the enormous potential of POZ‐TPy HTM in future perovskite applications.